During the project period further studies of demographic features of sickle cell disease will be carried out as follows: (a) further collection of demographic data on new patients, (b) updating of computerized data base information on old patients already entered into data file, (c) analysis of data base information using standard statistical tests, correlation matrices, regression analysis and population data analysis techniques. Prognostic indices and patient profiles will be constructed. Studies of endocrine function in adults will be completed including screening for basal hormone secretion and pituitary function and studies of sexual maturation. Studies of renal function in patients with sickle cell disease will be continued, particularly determination of parameters of chronic renal failure and documentation of the role of the parathyroid hormone in adjustments to chronic renal failure in patients with sickle cell disease (in comparison to patients without hemoglobinopathies. Central nervous system dsorders will be studied with further tests of neurological status of sickle cell patients with and without central nervous system lesions. Tests will include computerized analysis of EEG data,, computerized axial tomography, and nerve conduction tests. Further studies of red cell function, morphology and alteration by sickling will be carried out using nuclear magnetic resonance, biochemical techniques and specific drugs. Further studies of cardiopulmonary status will be carried out. Comprehensive care of individual patients, patient and community education, and vocational rehabilitation will continue to form central activities of the core program. BIBLIOGRAPHIC REFERENCES: Powars, Darleen: Natural history of sickle cell disease--the first ten years. In collaboration with L. Julian Haywood. Seminars in Hematology 12: 267-285 (July), 1975. Schroeder, W.A., Huisman, T.H.J., Powars, D., Evans, L., Abraham, E.C. and Lam, H.: Microchromatography of hemoglobins. IV. an improved procedure for the detection of hemoglobins S and C at birth. J. Lab. Clin. Med. 86:528 (September, 1975).